NAME
aio_return —
retrieve return status of an asynchronous I/O operation
(REALTIME)
SYNOPSIS
ssize_t aio_return(struct aiocb *aiocbp);
DESCRIPTION
The aio_return () function shall return
the return status associated with the aiocb structure
referenced by the aiocbp argument. The return status for
an asynchronous I/O operation is the value that would be returned by the
corresponding read(3), write(3), or
fsync(3) function call. If the error status for the
operation is equal to [EINPROGRESS], then the return status for the
operation is undefined. The aio_return () function
may be called exactly once to retrieve the return status of a given
asynchronous operation; thereafter, if the same aiocb
structure is used in a call to aio_return () or
aio_error(3), an error may be returned. When the
aiocb structure referred to by aiocbp is
used to submit another asynchronous operation, then
aio_return () may be successfully used to retrieve
the return status of that operation.
RETURN VALUE
If the asynchronous I/O operation has completed, then the return
status, as described for read(3),
write(3), and fsync(3), shall be
returned. If the asynchronous I/O operation has not yet completed, the
results of aio_return () are undefined.
ERRORS
The aio_return () function may fail
if:
- [EINVAL]
- The aiocbp argument does not refer to an asynchronous operation whose return status has not yet been retrieved.
EXAMPLES
None.
APPLICATION USAGE
The aio_return () function is part of the
Asynchronous Input and Output option and need not be available on all
implementations.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
aio_cancel(3), aio_error(3), aio_fsync(3), aio_read(3), aio_write(3), close(3), exec(3), exit(3), fork(3), lio_listio(3), lseek(3), read(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <aio.h>
CHANGE HISTORY
First released in Issue 5. Included for alignment with the POSIX Realtime Extension.
Issue 6
The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Asynchronous Input and Output option.
The APPLICATION USAGE section is added.
The [EINVAL] error condition is made optional. This is for consistency with the DESCRIPTION.
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